I do not think it is a spirit but a decision.
Yes, anyone can get jealous but it is up to you to decide whether or not to remain so.
For instance, I used to get freaking jealous when my boyfriend talks to other girls. Crazy isn't it? I mean, how in the earth was it possible not to talk to other girls? He wasn't cheating, NO, but I wanted him to talk to just me. I was being possessive. He used to heed until he came to the realization that it wasn't fair and he talked to me about it, I had to sit back and think about it, realizing that I was being possessive, I resolved to stop and started telling myself that he was free to talk to anyone and I was completely fine with it.
Though it didn't come easy, but with time, I accepted that fact and I stopped getting jealous about it.
Jealousy is something which kills us inside out. We only feel hate, showing complex emotion to a certain thing or person. It gives us the fear of abandonment and humiliation. So it is very normal for a person, I believe to be possess by the sprit of jealousy.
But you can always take control on yourself, whether you choose to go with your jealous mind or you can make yourself understand that it is okey. The second one is much more preferable for me. As you can not always take control of your surrounding so you should choose to be not influenced or forced by the sprit of jealousy. It will kill your inner-self slowly.
Taking a certain harmful decision, ruining a good relationship, breaking the understanding all comes from the same place, when we feel possessed by our jealousy. We have to first understand what we really need, how it is affecting us and then think about what should we do to get out from this harmful sprit.
It's more likely our choice, than a forceful sprit; how and what we want to show others, how we want others to treat ourselves. The control button is in your hand. You can always choose to not possessed by any sprit rather have control on your mind, decisions and attitude.
Yes, someone can be posses by jealousy though in our virtual world we are tend to disbelieve such practices. The true is , we live among spiritual being who are able to manipulate men in the physical realm.
For a case to be considered spiritual ,it ought to get to a point when one can't help himself no matter how hard he or she tries to. And the devil rejoices when we doesn't fight back in prayer rather relax in the comfort of his or her strength and the psychology of this world.
If the jealousy is extreme, I request she go on a fast with prayers. The Bible said the welfare of our wars are not canal but spiritual , breaking strong holds. If the Bible talks about spiritual battles and being, that means it does exist. And most times this beings control our day to day activities as well as manipulate our human emotions and body.
So if she is convinced that her situation is more than the physical then please let her commit it in prayer and fasting as well as pray for the Grace of love.
I don't think so. Jealousy depends on a person on how he reacts. It is within him, which can be normal, but if he exceeds with his reaction, then that is not normal. Some people go to the extent of killing others because of jealousy. Such attitude needs the help of a specialist to help control the emotion and mind of the person to avoid acting according to impulse. If you talk about the spirit which is unseen, I don't think so. But if it's a spirit pertaining to the attitude or innerness of a person, then yes.